I’m trying to spawn my ally character in a set position offset to the player, I really have no idea how to even designate the location period so at the moment they spawn at the world origin.
Something like this would try to spawn your Ally +100 X co-ordinates over from the location of your shooter character (with an empty FRotator which you could replace with GetActorRotation() for example to make them face the same way as you)
There are some other ways to try and collision test before you spawn your Ally to make sure it finds a good spot like capsule tracing or finding a random spot in navigable area around your character